Wasn’t windows phone discontinued like 10 years ago?

Apologies for being unclear, it's true Microsoft didn't have the option of Windows Phone for their Surface Duo devices, so they had no choice but to use Android. To clarify, when I phrase something as being an unwilling outcome it does not mean both were equally viable options and they picked the one they wanted, rather that Microsoft's hand was forced due to this development. I hope this helps.

Yes.